This application pertains to the art of video imaging, and more particularly to the art of formations of cine images in medical diagnostics imaging.
The invention is particularly applicable to medical imaging of the computed tomography ("CT") variety, and will be described with particular reference thereto. It will be appreciated, however, that the invention has broader applications such as in images generated by magnetic resonance or the like.
Non-invasive medical imaging is becoming an extremely useful and popular means by which valuable patient information is obtained. Presently, such images are obtained by computed tomography ("CT"), magnetic resonance ("MRI"), scintillation cameras, ultrasound, or the like.
Often such images are generated in a video display terminal ("VDT"), such as a cathode ray tube ("CRT"). Information for forming such video output is generally stored in digitized form in randomly accessible memory. The random access memory ("RAM") is selected via an address which specifies a memory location. That memory location stores information which dictates a small element of a picture or "pixel." A rectangular array of such pixels provides the video image. When a CRT is used as a display, memory which stores a video image is serially accessed and converted to analog, synchronously with a raster pixel clock and control signals, to provide a composite signal to generate a scan display.
The ability to provide sufficient information at an acceptable rate to a video memory becomes more difficult as image complexity increases. More complex images include more pixels or a greater palette of colors, and therefore require rapid access to more memory locations. This is further complicated when a series of individual images are to be serially displayed on a CRT in what becomes to be referred to as "cine" imaging.
Cine imaging provides for a means by which a series of related physiological images may be viewed serially. This provides a technician with valuable information on changes to a subject over a period of time.
Prior cine imaging was limited by a combination of pixel complexity of a display and the "shutter" speed at which sequential cine frames would be displayed. It would be desirable if a system could be provided with which a high resolution cine image would be displayable without perceptible flicker.
The present invention contemplates a new and improved cine imaging system which overcomes all of the above-referred problems, and others, and provides a high resolution, fast refresh, cine imaging system.